The word hamartano is found in two sections of Luke, used twice in each place. The first is where it is rendered as sin (Luke 15:18,21), and in the second as trespass. The first place is where the prodigal son confesses to his father that he has sinned. In the second passage, Jesus says that if our brother trespasses against us, we should forgive him upon repentance. And if he does the same thing seven times in one day, our response should remain constant.
Hamartia
is found eleven times in Luke. It was prophesied over John the Baptist as an infant that he would give knowledge of salvation to the people by means of remission of sins (1:77). And when John first started preaching, that is exactly what he did (3:3). A few chapters later, as with Matthew and Mark, the word is used when Jesus forgave the sins of the paralyzed man who was brought to Him, and the word is also used in the disputing afterwards (5:20,21,23,24). And when the sinful woman washed the Lord’s feet with her tears, the Lord forgave her sins (7:47,48,49). This is the word that Jesus taught us to use in the Lord’s prayer, when we ask for forgiveness of sins (11:4). And last, the Lord commissioned the Church to preach the gospel, preaching repentance and remission of sins in His name (24:47).